1. Field of the Invention
The present invention relates to a vulcanizing mould for moulding and vulcanizing a tire, and more specifically to a mould for moulding and vulcanizing a tire that has a tread pattern that allows the running noise of this tire to be reduced very appreciably.
2. Related Art
Document EP0876889 discloses a mould intended for moulding and vulcanizing tires. This mould comprises, radially internally, a moulding surface intended to mould the tread surface of the tires. The moulding surface is formed by assembling a plurality of mould segments.
FIG. 1 shows part of the moulding surface of this mould. This part of the moulding surface is formed by assembling two mould segments A, B.
The part of the moulding surface comprises a plurality of patterns organized in circumferential strips b1, b2, b3, b4, b5. Each circumferential strip comprises patterns derived from one and the same basic pattern. What is meant by a basic pattern is a design formed of a collection of protrusions and hollows arranged in a predetermined manner, this design being repeated n times in the circumferential strip.
In document EP0876889, each mould segment comprises several patterns belonging to the various circumferential strips and each mould segment comprises a single pattern of each circumferential strip. Thus, if each circumferential strip comprises n patterns, the mould then comprises n mould segments.
In order further to improve the acoustic performance of tires, it has been proposed for the number of patterns in the circumferential strips to be increased substantially and for the width of the patterns in the circumferential direction therefore to be decreased accordingly. Because the segments are narrower, they are then more fragile and the risks of these segments becoming damaged when they are being handled, for example when they are being fitted into the mould, increase.
There is therefore a need to improve the rolling noise reduction of tires while at the same time ensuring that the segments belonging to the mould used to mould the said tires are very robust.